My steps:
1) Removed license plate
2) Cleaned area with dish soap (non-citrus/degreaser) and water
3) I wet sanded the area with 600, and it took off the horrible exhaust marks really easily.
4) I taped off the area the best I could using your typical blue painter's tape. The corners were tough, but I masked off as best as I could. This is the hardest part IMO.
5) I had two big sheets of plastic and I covered the top/rear of the car with it. I secured it there by taping it to the existing painters tape on the bumper. I stuck the other sheet on the bottom of the car and made sure the rest of the car was hidden away from any possible overspray
6) I used Krylon's black primer spray paint. I took my time and covered up all areas which had red showing through. I put about two coats of it on the bumper. The primer is pretty light. I went through about a can.
7) The primer dries fast, so I didn't waste much time to throw the actual paint on it. I used Krylon's "rust-proof" spray paint, semi flat. This went on much quicker and thicker. I put about 3 coats of it on and used one can.
Results: (Sorry for the shitty cell pic)
http://img31.imageshack.us/img31/2342/ta2f.jpg
